Mold for hollow walls



0. KOFSTAD. MOLD FOR HOLLOW WALLS- APPLlcATloN FILED MAR. x4. |919.

1,345,371.- vPatemle 11u1y 6,1920.

i FIG 5' I6 25 FIG. 6.'

Br his Arrommw UNITED .STATES ,PATENT o rFicE.

oT'ro Korsiiii),A or `WARROAD, Miiviviiso'rn.-y

MOLD ron ViioLLow WALLS.v ,i

SpecificationV of Letters Patent. i

Application filed 'March '14, 1919. Serial No.1282,722.

T0 all whom t may] concern.'

Beit known thatv I, O'r'ro KorsTAD, a`

main object is to construct a concrete buildf ing having a double wall with a continuousv` air space between the walls or wall members all around the building. Another object is to provide an improved mold,1ncludi`ng a collapsible core'foribuilding such walls.

In the accompanying drawing:v

Figure 1 is av plan View of a pieceof ground with a corner portion ofl a building under construction by the use of my 1mproved mold and core. Fig. 2 is a side Velevation of the portion of Fig. 1 near above it. Fig. 3 is a right hand end view of Fig. 2. Fig. 4L is a section of the upper portion of Fig. 2, on the line 4-4 in either Fig. 1 or Fig. 2, with the cover 27 omitted. Fig. 5 is aside view and Fig. 6 is a top View of one of the bars 15 in the other views. Fig. 7 shows modified means for holding the side wall of the mold in plumb position. Fig.`8 is a detail view of the bracket 36 in Fig.` 7.

Referring to the drawing by reference numerals, 10 designates the ground upon which is usually provided a base 11, on which are molded of finer concrete than the base, parallel wall members 12 with a con- Y tinuousl air space 13 between them. The

only element traversing said air space in the finished wall is a series of spaced double wires, 14, which are preferably twisted, as best shown in Fig. 4 so as to stick firmly in the wall members. iow these wires are applied in the construction of'the wall will presently be more fully described.

The mold comprises several supporting bars 15, adapted to be placed across the base 11, or later on farther up inthe building Each of said across the two wall members. bars is provided in its upper side with notches 16, in which to guide and support planks or outer mold sections 17 and inner mold sections or members 18,V while intermediate mold members 19 rest in anotch 20. The upper edges of the mold members 17, 18, 19 are spaced by means of notched bars 21 placed across them and having their inner ends secured at 22 to posts 23, which may .be secured in upright position by any suit-v able means; and upon said'bars 21 may be'secured planks 24 for the workmen to walk on. i

The mold members 19 are spaced apart by several'rods 25, placed y'vertically between Patented July lc, i920.

the members and having each at the upper end a hook 26, which may rest upon one of the `planks 19,v as shown in Fig. 4, or the rod may hang through-ahole in a cover 27 and have the hook orliandle 26 resting inY a cavity 28 therein. Said cover 27 serves to prevent concrete or other things from dropping into the air-space; and the cavities 28 are to allow the handles 26 to sink suffi4 ciently down to be fairly out ofthe way for the tool used in leveling the top ofthe soft concrete even with the top of the mold.

Secured upon the members 17, 18, are vertical cleats 29 having their lower endsprovided with toes 30,v to which the wires 14 are f secured, preferably by placing'the middle of the wire over one of the toes and at the other.

toe twist the ends of the wire together, as shown at 31, after the wires have been placed across the wall members and in position to be received into notches 32 in the lower edgesof the'mold members, so as to allow the members to overlap slightly downwardly on the wall and rest on the bars 15.

The members 17 18 are also provided with other cleats, 33, preferably onV angle-iron stiff enough to prevent warping of the mold f In cases where it is inconvenient to use the bars or braces 21, extended to the posts 23, said bars may be cut short, as iniFig. 7 and provided each with a bracket 36, having a hole, or slot, 37 for a standing bolt 38, which is fixed in the section 18 and provided with a nut 39, which when drawn tight will cause the section to `assume a vertical position to v the bar 21, and thus stand plumb, because the bar 21 rests on member 17 and the memlbers 17 and 18 are of equal depth and restV at the same plane or level upon the bar 15; and if one mold member stands plumb, they -must all stand plumb, because of their connection with the plumb member through the notched bars 15 and 21.

i Hat core members and a series of removable In the operation of the device, the mold V1s placed about las shown in the drawing,

Vand concrete is illed in between the mold members up to the top of them, where it is then leveled off. After the concrete is set the'spacing rods 25 are pulled upward to allow the members 19V to' move toward each other and be removed; also the other mold members are removed for use higher up, the

last members removed are the bars 15, which being tapered, as shown in Figs. 5 and 6, are pulled out of the wall, their spaces in the wall filled with concrete and the/bars placedY in the notches 40, which during the operation just described were formed in the top of the Vwall members by the bars 21.

of the next higher layerI 'offconcrete After the wall is finished the projections lllX oi. the

wires 14 are cut away to Vleave the /iwall smooth. v l i -What I claim is:

l. A mold for vconcrete hollow wall conf struction, .the same comprising parallell fiat vertical moldV members adapted to form the inner and outer sides of the wall, a collapsible core spaced between said mold members, and means for holdng the moldmembers and the core in the desired relation `and position; said core composed of two. parallel The Y mold 1s then set up again for the formation holding means comprising several supporting bars adapted to be placed across the top oiithe 4wall,andhaving in theirupper sides notches for, the mold members and the core members to rest in, and upper'bars with notches in their undersides ior the upper edges of the mold members and core mem` bers, and means for holding said upper bars with the mold members invertical position.

3. The structure specified in claim 2, said supporting bars beingtapered from one end to the other, to facilitate their extraction from Vthe wall. f

4. The structure specified in claim 1'; saidLk mold members lhaving ufpon v'their outward sides vertical cleats with their lower'ends extending beyond the lmold members and provided with screws arranged to contact with their `ends against the wall, for the purpose set forth. v Y Y' In testimony whereof I my signature.

` OTTO jKOFSTAD. 

